Snoring and mild sleep apnea are generally thought to be the result of a reduced or partial constriction of the airway during sleep. This may be attributed to soft tissue sinking and applying pressure on the airway during sleep including the mandible dropping and moving backwards. Mandibular advancement devices are designed to move the mandible forward to relieve the force applied from soft tissue during sleep and assisting in opening the airway. Depending on the patient, the advancement of the mandible may vary based on the response of the patient. Optimizing the adjustment is referred to as titration.
Many devices are on the market today that serve to advance the mandible. A dual arch device comprising fins and an adjustment screw block are represented by Somnomed's Somnodent (U.S. Pat. No. 6,604,527), the Dynflex Dorsal Appliance, and Dr. Nordstrom's NorSnor II produced by Murdock Labs since the 1980's. Each device has an adjustable upper screw mechanism with block, which upon adjustment applies a force against a lower fin or bite block that then moves the mandible forward. The threaded screw system, requires that the user apply an Allen wrench to adjust the screw for titration. These devices are handmade and built up using polymethylmethacrylate (PMMA) and the corresponding monomer, methylmethacrylate. The device is cured in the dental lab and custom designed for each patient. Reproduction of the quality and accuracy of the device is subject to human skill.
Alternatively, there are devices that make an adjustment by changing out straps of different lengths to titrate the mandible forward. Examples of these are the Silent Nite (U.S. Pat. No. 5,365,945) produced by Glidewell, and the Narval (U.S. Pat. No. 7,146,982) produced by Resmed. These devices offer a possibly lower profile than the screw adjustment devices and also connect the upper and lower arch together.
Several limitations exist with these existing sleep apnea devices. First, the manual, artisanal fabrication method used by these devices limits the ability to consistently and precisely transfer the prescription into the device design. This limitation results in the need for additional adjustments. Second, the manual artisanal fabrication method requires the layering of monomers, which can subject the patient to higher levels of residual monomers. Third, existing device designs feature multiple components, straps, and screws that decrease durability, reliability, and ease of use. Fourth, the materials used in the manual, artisanal fabrication method require the device to be of a certain size to effectively withstand the normal intraoral forces that the device is subjected to. This size limitation results in decreased patient comfort and patient compliance.
Therefore a need exists to provide a mandibular advancement device that provides advancement of the lower jaw through a series of splints digitally designed and milled to provide accurate increments of advancement for easy titration of the mandible, without the need for an adjustment screw mechanism or adjustment straps.